Lower respiratory tract

Question 0

I don’t even know what Pneumonia is?

Answer 0

-inflammation of the lungs, accompanied by fluid filled alveoli and bronchioles

• hemoptysis - coughing up blood (bloody sputum)
• this is the most common infection that the elderly die of

Question 1

How many microorganisms are present in the lower respiratory system?

Answer 1

usually microorganisms are not present

sterile environment

Question 2

But wait, how do bacteria get into the lungs?

Answer 2

inhalation of aerosols: sneezing, coughing

aspiration of normal flora (inhaled from Upper respiratory tract or from GI tract)

Question 3

What is ‘hematogenous spreading’?

Answer 3

• infection is spreading from another part of the body gets into the blood, and can spread everywhere
• this is really not a good thing

Question 4

what would a productive cough indicate?

Answer 4

sputum. yum!

Question 5

What does an increase in PMNs, or an increase in Lymphocytes tell you?

Answer 5

• increase in PMN = neutrophils = increase in sputum

- increase in lymphocytes = viral infection

Question 6

Where could you get pneumonia?

Answer 6

in a hospital: second leading type of nosocomial infection, highest mortality rate of nosocomial infections

in your community

Question 7

How do you know if you have typical pneumonia? What signs?

Answer 7

• signs similar to pneumococcal: sudden onset, fever, chills, congestion, shortness of breath, chest pain
• productive cough
• bloody sputum

Question 8

What is the most common organism associated with typical pneumonia?

Answer 8

Streptococcus pneumoniae

Question 9

Characteristics of: Streptococcus pneumoniae

(for 70 of the adult population this stuff is just normal flora of the upper respiratory tract - but gets relocated to lungs (lower resp. tract) and causes problems!)

Answer 9

-remember this causes typical pneumonia
lobar
gram (+)
pairs or chains
Alpha hemolytic
blood agar

Question 10

Virulence factors Streptococcus pneumoniae

Answer 10

CAPSULE
Adhesin
IgA protease (destroy antibody)
pneumolysin (lyses epithelial cells)

Question 12

What factors would predispose you to a typical pneumonia infection?

Answer 12

• splenectomy (leave you at high risk for infections caused by organisms with capsules)
• alcoholism
• children
• elderly
• fall/winter (lots of people indoors)
• viral infection (influenza/HIV)

Question 13

If you are a doc and you suspect typical pneumonia, how could you make a diagnosis?

Answer 13

get a sputum sample!:

• rust colored (bloody)
• microscopy: gram (+) cocci, many PMNs
• antigen agglutination: secreted in urine as well as sputum
• look for alpha hemolysis on blood agar
• its optochin sensitive (chemical affects it and it wont grow up to disc)

Question 14

Is there a vaccine for typical pneumonia?

Answer 14

Yes.
-pneumovax (just capsule) is given to adults

• PVC (capsule conjugated with protein) is stronger and is given to those without a robust immune system - children
• anyone older than 65 should be both!

Question 15

What is the most common organism that causes atypical pneumonia (walking pneumonia)?

Answer 15

mycoplasma pneumoniae
#1 bacterial cause of atypical pneumonia

Question 16

What are the signs/symptoms of atypical pneumonia?

Answer 16

• non-productive cough (dry cough)
• fever, headache, malaise, myalgia, nausea, diarrhea, dyspnea
• excessive sweating
• could last weeks to months
• high school/college age students

Question 17

Characteristics of atypical pneumonia (mycoplasma pneumoniae)?

Answer 17

• capsule
• no cell wall
• adhesin (attachment to base of cilia)
• smallest free living microbe

Question 18

you suspect atypical pneumonia, how could you make a diagnosis?

Answer 18

• usually you can’t see it on the gram stain, so that wont work. (can see lots of PMNs tho)
• cold agglutinins test (+) - bind antibody even on ice!
• grows slow (2-6 weeks) on Lowenstein Jensen?
• PCR

Question 19

Second organism causing atypical pneumonia?

symptoms?

Answer 19

chlamydophila pneumonias

-milder infection (mild fever, sore throat, malaise, persistent cough)

Question 20

What are the characteristics of
chlamydophila pneumonias?

(how to diagnose?)

Answer 20

• obligate intracellular bacteria
• gram (-)
• community acquired

Diagnose - again no organism seen on gram stain, just a lot of PMNs

Question 21

Are their 1, 2, or 3 forms of chlamydophila pneumonia?

Answer 21

There are 2 forms.
Elementary body - form that gains Entry, infectious form.
Reticulate body - replicating form

Question 22

A third organism causing atypical pneumonia?

really? fuck :(

Answer 22

chlamydophila psittacosis

-disease of birds (parrot fever)
-transmitted to humans! ahh
(for test - poultry farmers, bird handlers

Question 23

Fourth organism causing atypical pneumonia?

what-EVER

Answer 23

legionella pneumophila

Question 24

legionella pneumophila characteristics?

Answer 24

gram (-)
in water cooling towers and air conditioning units
normal healthy adults don’t get this, they get a less severe form - Pontiac fever - because they have a healthy immune system.

Question 25

Who is at risk for legionella pneumophila?

Answer 25

• elderly
• smokers
• COPD
• high alcohol comsumption
• immunosuppressed
• renal transplant patients or patients on dialysis

Question 26

How could one diagnose legionella pneumophila?

Answer 26

• grows on a buffered charcoal yeast culture (fastidious grower)
• could use fluorescent antibody staining (can detect antigen in urine)

Question 27

Organisms that commonly cause nosocomial pneumonia

Answer 27

Pseudomonas aeruginosa
S. aureus
Enterics (not harmful in GI tract, but when aspirated…yeah not good)
H. influenza

Question 28

Can you please tell me the characteristics of pseudomonas aeruginosa?

Answer 28

yes. thanks for asking nicely.
-gram (-) rod
-Aerobic
-could grow in cold (fridge!)
-BIOFILM (alginate capsule)
flagella/pili (motile)
*sweet grape like odor
*green puss/sputum
*highly antibiotic resistant (bc nosocomial)
-opportunistic/oxidase positive

Question 29

Who is at risk for an infection caused by pseudomonas aeruginosa?

Answer 29

• Cystic Fibrosis (very susceptible to this, and many die from it)
• mucoid state allows for colonization (once colonized you will never be rid of it) super hard to treat, very resistant to antibiotic
• usually get S. aureus first
• can acquire it from a ventilator - if you are put on one in the hospital (must have been > 48 hrs to consider it nosocomial)
• not many virulence factors, its the IMMUNE system attacking the lungs!

Question 30

what produces copious amounts of foul smelling sputum?

Answer 30

Anaerobes

Question 31

Anaerobes characteristics

Answer 31

empyema - puss formation in pleural cavity

Question 32

What if I told you:

• gram (+) rods occuring in chains
• Aerobic non-motile
• forms resistant endospores (viable for 1000s of years)

Answer 32

Bacillus anthracis (causes anthrax)

Question 33

guess the types of anthrax (its not tough)

Answer 33

inhalation, cutaneous, Ingested

Question 34

Can you name an unusual characteristic of bacillus anthracis and other characteristics?

Answer 34

it has an Amino Acid capsule

it produces exotoxin (anthrax toxin)

Question 35

Why is bacillus anthracis so dangerous and used as a terror agent?

Answer 35

It spreads so easily in the air and the symptoms are so fucking generic you will never know that you have it, until its attacking the fuck out of you

Question 36

What do we mean by saying ‘anthrax toxin’?

Answer 36

that is an exotoxin (major virulence factor) secreted by the bacillus anthracis.
this thing has 3 protein components(released once bacteria is in blood stream):
-protective antigen
-edema factor (inc. in cAMP produces EF)
-lethal factor (causes death, appropriately named)

Question 37

Is there a vaccine for anthrax?

Answer 37

yes. it is given to certain military personnel and researchers

Question 38

For Bacillus anthracis, what can be seen on gram stain?

Answer 38

gram (+) rods, lots of PMNs (neutrophils)